Flat tire detector



Sept. 3, 1940. c. c. KITE 2,213,782

FLAT TIRE DETECTOR Filed Aug. 31, 1939 Patented Sept. 3, 1940 UNITED STTES PATENT? @FFHQE FLAT TIRE DETECTOR Claude C. Kite, Logansport, Ind.

Application August 31, 1939, Serial No. 292,919

6 Claims.

This invention relates to a flat tire detector and particularly of a construction adaptable to dual tires, and it consists in the constructions, arrangements and combinations herein described and claimed.

It is an object of the invention to provide a signalling means readily attachable to vehicles now in use and in which either or both of the dual tires actuate a switch mechanism for sounding the alarm.

More specifically, it is an object of the invention to provide an actuator lever adapted for positioning between a pair of dual tires, and including adjustable finger members for contacting engagement between the side walls of the tires, thereby regulating the time of actuation of the switch.

It is a still further object of the invention to provide a switch in which the actuator lever may be moved into a position to render the signalling means inoperative, as will be required when removing tires from the wheels of the vehicle.

Additional objects, advantages and features of invention will be apparent from the following description and accompanying drawing, wherein Figure 1 is a rear elevation of dual tires and a portion of the mounting therefor, illustrating my switch installed thereon;

Figure 2 is a side elevation thereof with the outer wheel removed.

Figure 3 is a longitudinal sectional view through the switch;

Figure 4 is a fragmentary cross sectional view thereof.

Figure 5 is an enlarged plan view of the tire engaging fingers.

There is illustrated in Figures 1 and 2 an axle it? upon which dual tires Ii are mounted, in side by side spaced relationship, as is customary. The 40 axle embodies a spring and shackle mounting 12 as well understood, which includes a bracket i3 having a vertically disposed collar M, the latter receiving a standard H5. The standard i 5 is vertically adjustable within the bracket and is fixed 5 by means of a set screw IE, or otherwise.

The standard i5 is of a length extending well above the tires i i whence it is bent at right angles to present an arm i'i lying above the tires. The arm i7 however, stops short of the outer tire so 50 that it will not present any projecting portion beyond the outer side wall of the tire.

The arm ll supports a switch 58 as will now be described, attention being invited to Figures 3 and 4 for an understanding of the construction.

55 The switch I8 is shown as circular, in formation embodying two identically constructed end plates IS. The plates I9 are constructed in the form of a disk, having an enlarged medial outer hub 2G for reception of the arm ii therethrough, and in order that the housing may be fixed upon 5 the arm, the hub is drilled and tapped to receive a set screw 2 i, the latter impinging upon the arm i! when screwed home.

Each plate l9 has a recess 22 upon their opposed faces into which the ends of a circular 10 casing 23 is seated. In order that the plates i9 may be securely retained in position, the end plates are apertured to receive tie bolts 2i, which firmly hold the plates is against the respective ends of the casing 23, these bolts also serving to 15 mount a spring tension means presently to be described.

An actuator arm 24 is oscillatably mounted upon the arm ill, and as shown comprises a pair of elongated steel straps arranged in parallel, 20 longitudinal relation, the upper ends of which are bent at right angles as at 25, in opposite directions, thence bent at right angles to define side walls 26. The side Walls 25 are apertured to receive the arm i'i therethrough and are then 25 bent to present portions 2'! parallel to the members 25. The portions 2? of the strap stop short of each other and each is provided with parallel opposed lugs 28. Between the lugs 28 an insulated wiper block 29 is positioned and held in 30 place by rivets or otherwise. It will be thus seen that the arm is oscillatably mounted upon the arm ii.

A tension spring 36 is mounted upon the arm El functioning to hold the arm 26 in inoperative position, and to this end the spring 3% comprises a bight 35 intermediate the ends of the spring, adapted to engage one of the rods 2 A suitable number of helices are employed upon either side of the bight 3 i, respective ends of the spring being 40 anchored upon the upper or outer edges of the side walls 26, as at 32.

The casing 23 has a slot 33 extending circumferentially a suitable distance, through which the arm 2 projects and may partake of the necessary oscillating movements. The lower edge of the slot 33 acts as a stop for the arm and if desired, the casing 23 may be reinforced, as at 34.

The arm 2 is presented between the dual wheels ii and extends forwardly approximately to a point in the vertical axis of the wheels, and in order that this may be attained, the arm 24 is given a slight curvature as at 35, so as to lie slightly spaced from the connecting hub of the dual wheels.

At the lower ends of the straps defining the arm 24 a spacer block 36 is fixed by means of suitable fastenings, and these fastenings also secure a pair of spring fingers 31. The fingers 3'! are outwardly bowed and lie in a position between the tires of the dual wheels so as to be contacted thereby when either or both of the tires becomes deflated to an undesirable extent.

In order that the setting or position of these fingers may be varied, a wedge block 38 is arranged betweenothe fingers in advance of the spacer block 38. The wedge block 38 has a threaded aperture for reception of a threaded stud 39 revolubly mounted in the spacer block 36. The wedge block 38 preferably has faces complemental to the fingers 31 and it will be apparent that by moving the block 33 longitudinally of the fingers, the spacing thereof may be varied, which is essential to accommodate various sized tires as well as to vary the time at which the signal is to be given.

Within the housing 23 an insulated contact 40 is mounted, having a stud M exteriorly thereof for connection of an electric lead 42.

Also mounted within the housing 23 there is a spring contact arm 53, one end of which is fixed to the housing, but insulated therefrom. A stud id is electrically connected to the spring arm 43 but insulated from the casing, the stud M also forming connection for a lead 55. The leads 42 and 45 are connected in any suitable circuit with a source of current and signal device, either visual or audible.

The spring contact arm 43 is of a length to extend beyond the contact till which normally lies spaced above, and the arm includes a cam portion 36 intermediate its length for engagement by the wiper block 2% of the arm 24.

In use, with the switch installed as described, should either or both of the tires become deflated or partly so, the tire or tires will tend to spread laterally, causing the adjacent side wall or walls to frictionally engage the fingers 37. Such engagement will cause a rearward movement of the arm 2G, as seen in Figure 2, bringing the wiper block 29 against the cam 56 with consequent movement of the spring arm 43 into engagement with the contact 80, closing the circuit to the signal means. As soon as the tire has been infiated, or repaired, the spring 36 will return the arm 24 to normal position.

When it is desired to change a tire or wheel,

the arm 24 may be swung fully upwardso that 1. A fiat tire detector for dual tires comprising a bracket positioned above the tires, a switch means carried thereby, said switch comprising an oscillatable actuator arm positioned between the tires, said arm having frictional contactwith the tires when under-inflated whereby to oscillate the arm to actuate the switch during rotation of the tires.

2. A flat tire detector for dual tires comprising a bracket positioned above the tires, a switch means carried thereby including a pair of binding posts for an electrical signal circuit, a switch arm electrically connected to one of the binding posts and normally spaced from the other binding post, an oscillatable actuator arm carried by the switch having contacting engagement with the switch arm, spring means for holding the actuator arm in normal position, said arm being positioned between the tires and having frictional contacting engagement with the tires upon loss of air therefrom, whereby to actuate the arm to move the switch arm into engagement with the last named binding post.

3. The structure of claim 2 in which the actuator arm includes adjustable spring fingers for establishing the frictional engagement with the tires.

4. A fiat tire detector for dual tires comprising attaching bracket having an arm extended at right angles above the tires, a casing fixed to the arm, an actuator arm having one end oscillatably mounted on the arm and positioned within the casing, the casing having a slot formed in its circumference and through which the actuator arm is extended, the terminations of the slots serving to limit movement of the actuator arm, said actuator arm having a length and. curvature to present the free end thereof between the dual tires, adjustable spring fingers carried by the free end of the actuator arm adapted to frictionally engage the side walls of the tires when under-inflated; a spring switch arm fixed at one end within the casing, an electrical contact adjacent the free end of the switch arm, a binding post for the contact, a second binding post electrically connected to the switch arm, spring means for holding the actuator arm in normal inoperative position but yieldable to force imparted to the actuator arm by the tires, and said actuator arm having a wiper block cooperable with said spring switch arm whereby to move the switch arm into engagement with said contact.

5. The structure of claim 4 in which the adjusting means for the spring fingers comprise a wedge block between the fingers and screw threaded means for moving the block longitudinally of the fingers.

6. The structure of claim 4 in which the switch arm comprises a cam portion complemental to said wiper block.

CLAUDE C. KITE. 

